Winding machine

ABSTRACT

A winding machine incorporating yarn traversing mechanism having a pair of oppositely moving belt spans, each provided with yarn engaging guides for moving the yarn along a traversal path in a controlled manner to wind a package of yarn, the yarn being transferred from one guide to another at each end of the path adjacent each package end. The traversal path of each of the spans is regulated so that the oppositely moving spans run parallel to the axis of the package in the zone corresponding to the axial midsection of the package. In the zones corresponding to the end sections of the package the oppositely moving belt spans run in paths diverging from said parallel paths. Stabilizing pulleys are provided to track the oppositely moving belt spans and thereby preclude vibrations being introduced into the yarn during its traversal.

United States Patent Primary Examiner-Stanley N. GilreathAttorneysAlbert P. Davis and Barnett W. Norton ABSTRACT: A windingmachine incorporating yarn traversing mechanism having a pair ofoppositely moving belt spans, each provided with yarn engaging guidesfor moving the yarn along a traversal path in a-controlled manner towind a package of yarn, the yarn being transferred from one guide toanother at each end of the path adjacent each package end. The traversalpath of each of the spans is regulated so that the oppositely movingspans run parallel to the axis of the package in the zone correspondingto the axial midsection of the package. in the zones corresponding tothe end sections of the package the oppositely moving belt spans run inpaths diverging from said parallel paths. Stabilizing pulleys areprovided to track the oppositely moving belt spans and thereby precludevibrations being introduced into the yarn during its traversal.

WENTEUFEMIQH 3565;359

mvnm m. WILLIA V ODHU E' BY 4.

ATTORNEYS WINDING MACHINE The present invention relates to a windingmachine and is directed more particularly to a winding machineincorporating improved traversing mechanism for guiding a strand of yarnonto a takeup package especially at very high speeds.

In the following specification and claims it is to be understood thatthe term yarn" is used in the general sense to apply to all kinds ofstrand material either textile or otherwise, and the designation packageis intended to mean the product of the winding machine whatever itsform.

In the'high-speed winding of yarn such as is practiced when extrudedpolymer filaments manufactured in melt spinning operations are taken up,it is known to use a winding machine incorporating traversing mechanismcomprising a.plurality of traversing guides or fingers connected tooppositely moving endless members such as belts, tapes, chains, etc.,for traversing the yarn to and fro axially of a package core to thuswind up the yarn into a package. Customarily the endless members move inopposite rectilinear paths and, at each end of the package, reversal ofthe yarn is effected by transferring the yarn from a first one of theyarn fingers moving in one direction to a second of the fingers movingin an opposite direction relative to the package core axis. In orderthat commercially acceptable yarn packages may be wound with thistechnique, it is necessary that reversal of the yarn at each end of thepackage be instantaneous and, further, that reversal occurs at the samepoint at each transfer, all so that the walls of the package will bestraight. To achieve this desired result it has been proposed to arrangethe opposite spans so that they move in rectilinear paths which are'atan angle inclined to the axis of the yarn package, the anglesof the twospans being equal to each other but inclined in opposite senses so thatthey cross each other in a line corresponding generally to the axialmidpoint of the package being wound. In practice with mechanisms of thistype the yarn is constrained to move in a path parallel to the packageaxis as it is moved to and fro by yarn engaging fingers on the spans.Consequently, as the yarn is moved from one end of the package to theother, engaged on a given yarn finger, the yarn slides outwardlyrelative to said finger and finally drops off over the tip of the fingerproximate to one end of the package. At this point an oncoming finger ona companion span moving in the opposite sense picks the yarn up to moveit toward the opposite package end, the yarnsimilarly sliding along saidfinger to a point where it ultimately drops offthe finger for engagementby a further oppositely moving finger. These repetitive steps take placeuntil a package of given diameter is wound.

The earlier movable spans were often constituted as chains or relativelystiff tapes driven by sprockets or wheels. However, increasing use hasbeen made of lightweight, flexible timing belts capable of operation atspeeds far in excess of that contemplated for the earlier chains andtapes. With the use of these timing belts it has become desirable toprovide intermediate idler pulleys to support the belts and controltheir tracking over the relatively long spans which they make. As shownin US. Pat. application Ser. No. 801,232 filed on Feb. 3, 1969, inventorHans l-l. Richter, for Strand Handling Equipment, an idler pulley isprovided for each belt span, the pulleys being disposed centrally alongeach span so that the tangent point of each belt with its pulley occursin the same plane at which the belt spans cross each other. This plane,as already suggested, is on a line corresponding generally to the axialmidpoint of the package being wound. In operation, it has been foundthat with the belts and pulleys arranged as just described anundesirable groove is formed in the periphery of the package as yarn iswound thereon. This groove is caused by each yarn finger beingaccelerated around that portion of the pulley with which the belt spancomes in contact. When it is remembered that the points of tangency ofboth belt spans with their respective pulleys are aligned with the samepoint on the yarn package it will be seen that the groove is accentuatedso that it is, in fact, twice the depth it might otherwise be if thetangent points of the belt spans with their idler pulleys were spaced.While a slight groove in the periphery of a package presents acommercially acceptable condition, an unusually deep groove such'asarises when the axis of the idler pulleys are aligned with reference tothe package may cause the yarn wraps or coils adjacent to the groove tocollapse into the groove and thereby render unwinding of the packagedifficult or even impossible.

The invention herein represents improvements upon traversing mechanismssuch as those just described wherein endless members are utilized forreciprocating yarn engaging fingers in opposite paths to traverse yarnonto a package core. According to the instant invention, there isprovided traverse mechanism wherein endless belts are arranged toprovide two oppositely moving spans each of which carries yarn engagingfingers for moving the yarn to and fro, axially of an associated yarnpackage core to distribute the yarn therealong as the yarn advances fromsupply source. The oppositely moving spans each are arranged to move ina first path generally parallel to the axis of the winding spindle andyarn core as the yarn is traversed onto a first zone of the core. Whenin this first path, the spans move in parallel courses in the regioncorresponding to the midsection of the associated yarn core and packagewound thereon. The oppositely moving spans are further configured sothat they incline relative to the axis of the package core proximate tothe end sections of said core and of the package being wound thereon. Byvirtue of the unique and advantageous arrangement for the belt spans asprovided herein, the winding machine is capable of providing a woundyarn package wherein the periphery of the package is virtuallycylindrical along its entire surface, substantially free of grooves orother imperfections and wherein the yarn is traversed axially of thepackage by means of oppositely moving belt spans which are stabilized toafford vibration free control of the yarn during its traversing.

An object of the present invention is to provide a yarn traversingmechanism suitable for operation at high speeds.

A further object of the invention is to provide a traverse mechanismcapable of traversing yarn at high speeds onto a core to form a packageof yarn having a virtually cylindrical and grooveless surface from oneend of the package to the other.

Another object of the present invention is to provide a traversingmechanism for traversing yarn axially of a rotating core to wind apackage and for controlling the point of reversal of the yarn withaccuracy to thereby form a package with rigid end walls.

Another object of the present invention is to provide traversingmechanism employing oppositely moving endless belt spans which arestabilized by means of intermediate idler pulleys axially spaced onefrom the other.

An additional object of the present invention is to provide traversingmechanism utilizing endless belt spans for moving the yarn to and froaxially of the rotating package core to wind a package of yarn thereon,the endless belt spans being movable in parallel paths as the yarn istraversed on the midsection of the package and the belt spans moving ininclined paths toward the end sections of said package end core. Otherobjects of the invention will in part be obvious and will in part appearhereinafter.

The invention accordingly comprises the apparatus possessing theconstruction, combination of elements and arrangement of parts which areexemplified in the following detailed disclosure in the scope of theapplication of which are exemplified in the following detaileddisclosure in the scope of the application of which will be indicated inthe claims.

For a fuller understanding of the nature and objects of the inventionreference should be had to the following detailed description taken inconnection with the accompanying drawing wherein:

FIG. 1 is a perspective view of a conventional yarn takeup machineincorporating the novel traversing mechanism of the present invention;

FIG. 2 is a top plan view of the traversing mechanism of the apparatusof FIG. 1; and

FIG. 3 is a perspective view of the traversing mechanism of FIG. 2.

From a broader general view the present invention contemplates theprovision of a pair of endless timing belts each of which is providedwith a plurality of yarn traversing fingers. The fingers are supportedon their respective belt spans and extend laterally therefrom. The beltsare carried on respective guide means such as timing pulleys which serveto track and drive the belt. It will be appreciated that each of thebelt spans moves in a direction opposite to the other to thereby effecttransversal movement of the yarn axially to and fro relative of arotatable package core mounted on an associated winding machine tothereby wind a package. When viewed in the vertical plane the oppositebelt spans are guided so that they operate along parallel courses in thezone corresponding to the general midsection of the core and yarnpackage being wound thereon. In the zones corresponding to the endsections of the package and its core the belt spans are arranged whenviewed in the vertical plane to move in inclined planes relative to theaxis of the package core. This feature facilitates transfer of the yarnfrom one of the yarn engaging fingers advancing the yarn in onedirection to an oncoming finger for yarn movement in the oppositedirection. Thus, accurate reversal of the yarn at each end of thepackage is achieved.

Referring now, in detail, to the drawing wherein a preferred embodimentof the present invention is illustrated, and with particular referenceat the outset to FIG. 1, there is shown winding mechanism designatedgenerally at mounted on a pedestal or base 12. The winding mechanism 10is of the type known in the art as a "precision winder wherein thenumber of rotations of the spindle 14 to each reciprocation of the yarnacross the package is fixed from the start of the winding operationuntil the package P being wound is completed. The winding mechanismshown comprises a spindle 14 rotatably journaled in a casing 16. Spindle14 is provided with an expansible and contractile package core holdershown generally at 18 for releasably mounting a package core 20 on saidspindle. Means such as an operating handle (not shown) is provided forcontracting the package core holder 18 when it is desired to remove afull yarn package P therefrom and replace it with an empty package coreprior to commencing the winding of a new package. The winding mechanism10 is driven by suitable means such as an electric motor (not shown)which may be mounted within base 12 and connected with spindle 14 viasuitable drive means such as a driving belt. The motor may be wound sothat is has variable speed characteristics, that is to say, the speed ofthe motor would increase or decrease as the electrical current suppliedthereto is increased or decreased. Tensioning means such as a dancer arm22 is provided which has a yarn receiving element 24 connected to theouter end thereof. The yarn receiving element operates to engage theyarn Y flowing from its source of supply and guide the yarn for windingonto package P while the yarn receiving element 24 and its rockablemounting arm 22 function to control the tension in the yarn during itstake up. All of the foregoing structure is old and well known in the artand further description thereof is not deemed necessary herein, thepreceding discussion being presented in the interest of providing aclear and concise understanding of the present invention.

With continuing reference to FIG. 1 it will be observed that the yarnflows downward from its supply source to the yarn engaging element 24,where the path of the yarn is reversed to direct it upwardly from saidyarn engaging element 24 to be engaged by traversing mechanismreferenced generally by the numeral 30 which serves to reciprocate theyarn axially of the package core 20 and thereby distribute the yarnalong said core to thus wind the package P. In the course of its upwardmovement the yarn passes through a channel 32 (FIG. 2) which is definedon one side by the front straight wall 34 of the housing surroundingtraverse mechanism 30. The opposing wall of channel 32 is formed by abar 36 fastened at its ends by means of screws 37 to the end sections offront wall 34. It will be seen in FIG. 2 that bar 36 is spaced from saidwall 34 over its major length to thus afford clearance constitutingchannel 32, said channel running parallel with the axis of spindle 14.Further guide means for the yarn advancing to package P is provided by aroller bail 38 which is situated proximate to the front end of traversemechanism 30. This roller bail is rotatably supported at its ends inbearings 39 and provides a rotational surface on which package P issupported during its winding. Yarn Y is guided onto package P throughthe nip defined at the contact line of package P with roller bail 38.

With reference now to FIGS. 2 and 3 wherein the traversing mechanism 30is shown in detail, said mechanism includes a pair of endless timingbelts 40, 42 movable at constant speeds in opposite directions, asindicated by the arrows in FIGS. 2 and 3. Means for guiding and trackingthe timing belts 40, 42 are constituted as a series of timing pulleys.Thus, a first series of pulleys 44, 45, 46 and 47 are provided forguiding the upper endless belt 40 and, similarly, a further series ofsprockets 48, 49, 50 and 51 are situated so as to guide and track thelower endless timing belt 42. The drive means for belts 40, 42 may bethe same as that fully illustrated and described in commonly assignedcopending U.S. application Ser. No. 801,232 previously cited. Guidepulleys 44, 45, 46 and 47 are mounted on respective stub shafts 54, 55,56 and 57 via ball bearings (not shown), the outer races of the bearingsbeing press fitted in recesses provided inside the top wall 58 oftraversing mechanism 30. The timing pulleys 48, 49, 50 and 51 whichserve to guide and track the lower belt 42 are mounted in a similarmanner to that just described in connection with the pulleys whichsupport the top belt 40. Thus, a stub shaft 62 is provided for mountingpulley 48. Similarly, a stub shaft 63 mounts pulley 49, and further stubshafts 64 and 65 mount pulleys 50 and 51, respectively. The stub shafts62, 63, 64 and 65 are rotatably carried on ball bearings (not shown)which are press fitted into suitable recesses provided in the bottomwall 66 of traverse mechanism 30. As is most apparent in FIG. 2 and FIG.3 each of the belts 40, 42 has mounted thereon at spaced positions apair of yarn engaging fingers 68 each of which is adapted to projectthrough an elongated slot 69 formed in front wall 34 of the traversemechanism 30 and traverse the yarn axially of the package consistentwith the direction of movement imparted thereto by its mounting belt 40or 42. These fingers and their mode of mounting on the respective belts40, 42 are fully shown and described in aforementioned U.S. Pat.application Ser. No. 801,232 and further discussion of the configurationof the fingers and the means for mounting these fingers on the belt isnot deemed necessary herein.

Viewing FIGS. 2 and 3, it will be observed that stub shafts 54 and 62and stub shafts 57 and 65 are in coaxial alignment. However, incontradistinction thereto, it will be observed that the axis of stubshaft 55 is offset from the axis of stub shaft 64 both in the horizontaland vertical planes. Similarly it will also be seen that the axis ofstub shaft 56 is offset horizontally and vertically from the axis ofstub shaft 64. As will be more fully related hereafter, the offset axesof stub shafts as just described contributes to effective transfer ofthe yarn from one yarn finger 68 to another as the yarn reaches othereach end of the package.

A further unique feature of the instant invention is the provision of apair of relatively large stabilizing pulleys 70 and 72 which arerotatable on spaced-apart stub shafts 74 and 76, respectively positionedwithin the housing of traverse mechanism 30. As is seen in the drawing,the enlarged pulley 70 spans the width between the front run 40a of belt40 and the rear run of 40b of said belt 40 to thereby simultaneouslyengage both the front and rear runs of said belt 40 and providestability thereto as these elongated runs reach between pulley 47 andpulley 44, and between pulley 45 and pulley 46. In like manner theenlarged pulley 72 is of sufficient diameter to engage the front span of42a and the rear span 42b of belt 42. Thus, this latter pulley providesstability to belt 42 in its elongated reach between pulleys 51 and 48and between pulleys 49 and 50.

The unique arrangement of pulleys as provided by the present inventionsituates eachv of the belts 40, 42 advantageously for traversing theyarn .Y onto package P and, coincidently therewith, for controlling themovement of the respective belts with minimal .vibration. Thus,considering, firstly, the specific orientation of belt 40, and as bestseen and traced with reference to the arrows in FIG. 2, this belt movesin an inclined path from pulley 44 andpas'ses partially around pulley45. Said pulley 45 is mounted so that belt 40 is delivered tangentiallytherefrom to pulley 70 along a rectilinear path a-a, said path beingparallel to channel'32 and to the axis of spindle 14.-From its tangentpoint on pulley 70 the belt 40 declines to engage and be guidedpartially around pulleys 46 and 47 whereuponthe belt is moved in anextended run 405 to once again pass partially around pulley 44. Aspreviously discussed, belt 40 engages tangentially with intermediatepulley 70 in its rearward'run 40b to thus be supported over this ratherextensive pass.

With reference now to belt 42 and considering its path of movement, saidbelt 42 makes a partial wrap around pulley 51 and inclines upwardly atrather a steep angle to make a partial pass around pulley 50 and thenrun rectilinearly in a path b-b to engage tangentially with pulley 72,arid-the'reafter to decline at any a an angle to wrap partiallyaroundpulleys 49 and 48. From pulley 48 belt 42 extends in its rearward run42b to once again make a partial pass around pulley 51. In the course ofits movement in path b-b the belt moves parallel to channel 32 and theaxis of spindle 14. Furthermore, paths a-a of belt 40 and bb of belt 42are vertically aligned, as best seen in FIG. 2. Hence, it follows thatin the zone -0 the two belts 40 and 42 move in parallel, verticallyaligned paths, said paths being also parallel to the axis of spindle l4and channel 32. The zone c-c is perpendicular to the axial rnidsectionofpackage P.

As already described, belts 40 and 42 diverge or move in inclined pathsupon moving out of their zone of parallelism at 0-0 and on thedownstream side' thereof. This feature facilitates transfer of the yarnfrom an active yarn engaging finger 68 on one of the belts for movingthe yarn in one direction axially of package P to an oncoming fingercarried.

on the opposite belt for traversing the yarn in the opposite direction.These diverging or inclined paths are perpendicular to end sections ofthe package and result from the axes of pulley 45 and 49 and the axes ofpulleys 46 and 50 being offset from each other. Viewing FIG. 2 belt 40is seen to incline downwardly from intermediate pulley 70 to its guidepulley 46, carrying with it a yat'nengaging finger 68. Consequently,since the yarn Y is constrai'netlto move in a straight path by virtue ofits engagement in channel 32, the yarn will gradually move outwardlyrelative to saidfinger for ultimate disengagement therefrom. At thereversal point, which corresponds with the end of the package P, theyarn slips off the end of said finger 68 and is instantaneously engagedby an.oncoming finger 68 carried on belt 42. This oncoming finger isaligned to seize the yarn Y immediately due to it's being advancedforwardly or upwardly into the yarn-path as its belt 42 is guided overthe forwardly located pulley'50.

Precisely the same action takes place for reversing the traversalmovement of the yarn at the right-hand end of package P as seen in FIG.2. That is, belt 42 inclines downwardly from the right hand end of itszone c-c toward pulley 45, thus carrying a finger 68 which is engagedwith yarn Y downwardly therewith. As a resultof this movement the yarngradually slips toward the end of finger 68 and eventually off the endof the finger. Simultaneously with the release of the yarn by saidfinger, a further finger 68 on belt 40 engages the yarn to carry it tothe opposite end of the package. This repetitive action continues untilpackage P is wound to its desired diameter.

Since path H of belt 40 and path b-b of belt 42 are parallel to the axesof channel 32, package P and spindle 14 the belts are operated in theireffective traversing zones with a minimum of vibrations. Additionallythe amplitude of vibrations is varied between the front runs 40a and 42aof belts 40 and 42 respectively since the zone where the longer reach ofrelative to the axis of package P. Therefore, the tendency of a grooveto develop on the package periphery as fingers 68 accelerate around aportion of either pulley 70 or 72 is significantly reduced.

lclaim:

l. A yarn winding machine comprising, a rotatable spindle, first meansfor traversing an advancing strand of yarn axially of said spindle in afirst direction, second means for traversing the yarn axially of saidspindle in a second direction, traversing of the yarn by said first andsecond means serving to distribute the yarn to form a yarn package,guide means operable to direct said first and second means in respectivefirst paths as the yarn istraversed onto related first zones of saidpackage and in respective second paths as the yarn is traversed ontorelated second zones of said package, at least a portion of said firstpath of said first means and at least a portion of said second path ofsaid second means being generally parallel to each other in a commonplane spaced from said package.

2. The combination as set forth in claim 1 wherein said first and saidsecond means each comprises respective first and second endless spans.

3. The combination as set forth in claim 2 including rotatable means fordirecting the paths of said first and second spans.

4. The combination as set forth in claim 3 wherein said rotatable meansis operable to move said first and second spans in opposite directions.

5. The combination as set forth inclaim 2 wherein each of said first andsecond spans includes at least one yarn engaging member thereon formovement therewith.

1. A yarn winding machine comprising, a rOtatable spindle, first meansfor traversing an advancing strand of yarn axially of said spindle in afirst direction, second means for traversing the yarn axially of saidspindle in a second direction, traversing of the yarn by said first andsecond means serving to distribute the yarn to form a yarn package,guide means operable to direct said first and second means in respectivefirst paths as the yarn is traversed onto related first zones of saidpackage and in respective second paths as the yarn is traversed ontorelated second zones of said package, at least a portion of said firstpath of said first means and at least a portion of said second path ofsaid second means being generally parallel to each other in a commonplane spaced from said package.
 2. The combination as set forth in claim1 wherein said first and said second means each comprises respectivefirst and second endless spans.
 3. The combination as set forth in claim2 including rotatable means for directing the paths of said first andsecond spans.
 4. The combination as set forth in claim 3 wherein saidrotatable means is operable to move said first and second spans inopposite directions.
 5. The combination as set forth in claim 2 whereineach of said first and second spans includes at least one yarn engagingmember thereon for movement therewith.